Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS6101378 A
Publication typeGrant
Application numberUS 08/698,508
Publication date8 Aug 2000
Filing date15 Aug 1996
Priority date15 Aug 1996
Fee statusLapsed
Also published asCA2213037A1
Publication number08698508, 698508, US 6101378 A, US 6101378A, US-A-6101378, US6101378 A, US6101378A
InventorsDarrell Barabash, Russell Morris
Original AssigneeJapan Radio Co., Ltd.
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Pre-paid cellular telephone system
US 6101378 A
Abstract
A cellular telephone system maintains a database of prepaid cellular telephone service accounts, including an amount of money remaining in each account. The system uses modems in a blank-and-burst mode to send data and commands over a voice channel. When a call is attempted over a mobile unit, the system sends identification information stored in the mobile unit to a debit processing unit, which then permits the call and debits the associated account if a sufficient amount of money remains in the account, otherwise it terminates the call.
Images(3)
Previous page
Next page
Claims(19)
What is claimed is:
1. A radiotelephone system for providing prepaid mobile telephone service to subscribers, comprising:
(a) a plurality of mobile telephone units, each:
(i) being associated with one of the subscribers;
(ii) storing an identification of the associated subscriber; and
(iii) including a first modem being capable of sending the identification of the associated subscriber whenever a call is attempted over the mobile telephone unit;
(b) a plurality of base stations, each of said base stations having means for establishing a voice channel between it and one of said mobile telephone units for each call initiated or received at said mobile telephone unit and said base station also having means for controlling calls and providing control information and power level information between said base station and one of said mobile telephone units for mobile telephone service being provided to said mobile telephone unit; and
(c) a debit processing unit having a link to at least one of said base stations and also having:
(i) means for storing a database, for each subscriber the database contains a balance of money remaining in an account corresponding to the subscriber;
(ii) a second modem connected to a point along the voice channel, said second modem being in data communication with said first modem, said second modem including means for receiving information over said voice channel established by said base station in bursts in a blank-and-burst format, the first and second modems sending signals to and receiving signals from each other in bursts, each said burst comprising a synchronization word having a variable error threshold and said synchronization word for enabling one of said modems that is receiving said burst to differentiate the burst from the voice signals carried over the voice channel, the voice signals being muted during each burst, whereby the first and second modems provide a data channel between the mobile telephone unit and the debit processing unit seemingly concurrently, and with minimal interference with the voice signals that are being carried over the voice channel, and without requiring modifications to the base station, and wherein said information being sent over the voice channel includes the identification of the associated subscriber sent by one of the plurality of mobile telephone units when a call is attempted over the mobile telephone unit; and
(iii) means for selectively permitting, over said link, the call to be connected if the balance of money remaining in the account corresponding to the associated subscriber exceeds a first specified amount, and if the call is permitted, reducing the balance of money remaining in the account corresponding to the associated subscriber; and
(iv) means for denying, over said link, said call by sending a command to said mobile unit associated with the subscriber to terminate the call if said balance is below said first specified amount.
2. The radiotelephone system defined in claim 1, wherein said synchronization word:
is a 16-bit code word.
3. The radiotelephone system of claim 1, wherein said link between said base station and said debit processing unit is one of permanent, switched, wire or wireless.
4. The radiotelephone system defined in claim 1, wherein the first and second modems use audio frequency-shift keying (AFSK) to respectively send and receive the identification of the associated subscriber.
5. The radiotelephone system defined in claim 4, wherein:
(a) the first and second modems respectively send and receive the identification of the associated subscriber in at least one burst of data;
(b) the first modem sends a synchronization word at the beginning of each burst of data;
(c) the second modem detects the beginning of each burst of data by the presence of the synchronization word; and
(d) the associated mobile telephone unit mutes the voice signals during each burst of data.
6. The radiotelephone system defined in claim 1, wherein during a call, the debit processing unit:
(a) periodically reduces the balance of money remaining in the account corresponding to the associated subscriber; and
(b) if the balance of money remaining in the account corresponding to the associated subscriber becomes less than a second specified amount, terminates the call.
7. The radiotelephone system defined in claim 6, wherein:
(a) at least one of the plurality of mobile telephone units further comprises means for displaying the balance of money remaining in the account corresponding to the subscriber associated with the mobile telephone unit; and
(b) the debit processing unit periodically causes the at least one mobile telephone unit to display the balance of money remaining in the account.
8. The radiotelephone system of claim 7, wherein each said burst of said blank-and-burst communication further comprises an acquisition header for enabling one of said first and second modems that is receiving a signal in said burst to clock-synchronize with the remainder of the burst.
9. The radiotelephone system of claim 8, wherein said acquisition header is a code of between 12 and 20 bits.
10. The radiotelephone system of claim 8, wherein each burst further comprises a subframe for transporting data, the data comprising groups of data bits, the sub-frame comprising code words, wherein each group of data bits is encoded to form one of the code words.
11. The radiotelephone system of claim 10, wherein a forward error correction code is used to encode each group of data bits to form one of the code words.
12. The radiotelephone system of claim 11, wherein the forward error correction code is a (15,11) Hamming code.
13. A method of providing prepaid mobile telephone service to subscribers, in a mobile telephone system having a plurality of mobile telephone units each including a first modem and each being associated with one of the subscribers, and a plurality of base stations which establish a voice channel between the base station and a mobile unit for each call initiated or received at said mobile unit and said base station, and a second modem connected to a point along the voice channel, said second modem being in data communication with said first modem, the method including the steps of:
(a) storing an identification of one of the subscribers in each said mobile telephone unit;
(b) storing a data base in an associated data storage device containing the subscriber's identification and a balance of money remaining in an account corresponding to that subscriber;
(c) when a call is initiated by one of said subscribers, establishing a voice channel between said mobile telephone unit of said subscriber and said base station;
(d) transmitting the subscriber's identification and corresponding balance of money remaining in an account over said voice channel in a burst of data over said voice channel, including:
1. sending at the start of said burst a synchronization word having a variable error threshold, and said synchronization word for enabling one of said first and second modems that is receiving said burst to differentiate the burst from the voice signals carried over the voice channel;
2. muting said voice signals during each said burst;
3. selectively permitting the call to be connected if the balance of money remaining in the account corresponding to the associated subscriber exceeds a predetermined amount, and denying the call if said balance is below a predetermined amount;
4. upon permitting the call, reducing the balance of money remaining in the account corresponding to the associated subscriber.
14. The method of claim 13 including said synchronization word being a 16-bit code.
15. The method of claim 13 including the step of:
sending as a component of said burst an acquisition header for enabling one of said first and second modems that is receiving a signal in said burst to clock-synchronize with the remainder of the burst.
16. The method of claim 15 including the step of:
sending said acquisition header as a code of between 12 and 20 bits.
17. The method of claim 16 including the step of:
sending as a component of said burst a subframe for transporting data, the data comprising groups of data bits, the subframe comprising code words wherein each group of data bits is encoded to form one of the code words.
18. The method of claim 17 including the step of:
encoding each group of data bits of said burst using forward error correction.
19. The method of claim 18 including the further step of:
employing a forward error correction code that is a (15,11) Hamming code.
Description
BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to cellular telephone systems and, more particularly, to such systems that provide prepaid cellular telephone service.

2. Description of the Related Art

In an effort to minimize defaults in payment for services, a provider of cellular telephone services may refuse to enroll a new subscriber unless the subscriber has a credit rating that exceeds certain minimum standards. Consequently, potential cellular telephone subscribers who have poor credit ratings cannot obtain cellular telephone service, even if they are financially capable of paying for it. In addition, a subscriber who meets the minimum credit standards exposes himself to potentially large bills if his mobile telephone unit (mobile unit) is used fraudulently or if a thief alters another mobile unit to mimic the "electronic serial number" (ESN) of the subscriber's mobile unit. Furthermore, some potential cellular telephone subscribers would prefer to subscribe for short periods of time, e.g., during a business trip or while traveling on vacation, but the providers of cellular telephone services generally require new customers to enroll for at least one year and bill only for whole-month periods.

SUMMARY OF THE INVENTION

The invention is a cellular telephone system in which a subscriber prepays for cellular telephone services and the system completes a call only if a sufficient balance of money remains in the subscriber's account to cover the cost of the call. The system thus enables providers of cellular telephone services to provide prepaid services to subscribers regardless of their credit ratings. A subscriber can also budget his use of the cellular telephone system by periodically, e.g. monthly, prepaying for the service. In addition, a subscriber can limit his liability for fraudulent use of his mobile unit to the balance in his account.

The system maintains a database containing the balance of money in each subscriber's account and it debits the account as the subscriber's mobile unit makes or receives calls. When a user attempts to make a call with a subscriber's mobile unit or when another party attempts to call the mobile unit, the mobile unit communicates, i.e., exchanges data, with a debit processing unit (DPU), which accesses the database to ascertain whether the subscriber's account contains a sufficient balance for the proposed call. If not, the DPU instructs the system to deny the call and, optionally, it instructs the mobile unit to disable itself from attempting further calls. On the other hand, if the account contains a sufficient balance, the DPU instructs the system to complete the call. During the call, the DPU periodically debits the account for air time and toll charges incurred as a result of the call and, if the balance becomes insufficient for additional air time or toll charges, the DPU can instruct the system to terminate the call.

The mobile unit communicates with the DPU by sending and receiving bursts of data over the voice channel of the cellular telephone system. Advantageously, exchanging data over the voice channel avoids requiring the service provider to seek regulatory approval or make any changes to existing base stations. The mobile unit and the DPU each employs a modem to modulate the data onto the voice channel, preferably using audio frequency-shift keying (AFSK). Preferably, the system uses a technique known as "blank-and-burst," in which the system disables the normal audio path during a burst of data to avoid voice-signal interference with the data. The bursts do not significantly degrade the normal voice signals because the bursts are short, i.e., generally less than one second in duration.

The modems overcome the problem of differentiating data signals from voice signals by constantly sampling the signal carried over the voice channel to detect the beginning of a burst of data. Each burst contains with a predetermined pattern of bits (a "synchronization word") near its beginning that enables the receiving modem to identify the burst. The bit pattern of the synchronization word is chosen to minimize the probability that normal signals carried over the voice channel, e.g., speech, facsimile signals or computer modem signals, contain the modulated-equivalent of the synchronization word.

The system thus provides a data channel between the mobile unit and the DPU. The data channel can be used seemingly concurrently, and without interfering, with the normal voice signals to send commands and/or data between the mobile unit and the DPU. For example, during a call the DPU can periodically send the balance remaining in the subscriber's account and the mobile unit can display this balance on its display screen to keep the subscriber apprised of the balance. Optionally, when making or answering a call, the user of the mobile unit can enter a maximum amount of money that he wishes to have debited as a result of the call. When this amount has been debited, the mobile unit, or optionally the DPU, can automatically terminate the call after giving an appropriate warning message. Data transmitted over the data channel can be encrypted so that, for example, a user can be required to enter a personal identification number (PIN) before making or receiving each call. After encrypting the PIN, e.g. using an algorithm that includes a time stamp, the mobile unit can send it to a base station or DPU for validation with little chance of its being intercepted by a potential thief.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and further advantages of the invention may be better understood by referring to the following description in conjunction with the accompanying drawings, in which:

FIG. 1 is a block diagram of a wireless communication system according to the present invention;

FIG. 2 is a less detailed block diagram of a larger wireless communication system than the one shown in FIG. 1; and

FIG. 3 is a diagram of a data burst.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 depicts a radiotelephone system 100 according to the present invention, in which a base station 102 is in two-way radio communication with a mobile unit 104 and is connected to a debit processing unit (DPU) 106 by a link 108. The link 108 can be provided over a public switched telephone network (PSTN) or over a separate link. The DPU 106 is connected to the PSTN 110 through a DPU-PSTN interface 112. Under the control of a DPU controller 114, the DPU 106 selectively permits or prevents the completion of calls between the mobile unit 104 and a dialed or dialing telephone unit (hereinafter collectively referred to as a "dialed unit") 116 on the PSTN 110 depending on whether a database 118 indicates that a sufficient balance of money remains in the appropriate account.

As shown in FIG. 2, one DPU 106 can be connected to several base stations 102 and can control calls involving many mobile units 104. The links 108 between the base stations 102 and the DPU 106 can be permanent or switched, wire or wireless connections, preferably over the PSTN 110. Alternatively, the DPU 106 can be co-located with one of the base stations 102.

Referring again to FIG. 1, conventional air interface units 120 and 122 in the mobile unit 104 and the base station 102, respectively, together with antennas 124 and 126 provide a voice channel between the mobile unit and the base station and handle such functions as selecting a radio frequency and transmitter power level for the voice channel. A base station PSTN interface 128 extends the voice channel over the link 108 to the DPU 106. When the DPU 106 permits a call, the DPU extends the voice channel over the PSTN 110 to the dialed unit 116.

Under the control of a mobile unit controller 130, an audio interface unit 132 selectively connects a speaker 134 and a microphone 136 to the voice channel, as described below. When the speaker 134 and microphone 136 are connected to the voice channel, a user can converse with a party at the dialed unit 116. Of course, the voice channel can carry signals, such as computer modem signals and facsimile signals, as well as speech signals. All conventional user-initiated signals carried over the voice channel are herein collectively referred to as "voice signals."

A modem 138 in the mobile unit 104 and a modem 140 in the DPU 106 can each be selectively connected to the voice channel and thus provide a data channel over which the mobile unit controller 130 can communicate with the DPU. Various types of modems, such as quadrature amplitude modulation (QAM) modems can be used, but we prefer to use an audio frequency-shift keying (AFSK) modem because AFSK is less sensitive to imperfections in the voice channel and is generally more cost effective.

The modems 138 and 140 send data in one or more bursts. The receive portions of the modems 138 and 140 are always connected to the voice channel so each modem can detect the beginning of any data burst that is sent by the other modem. However, the transmit portion of each modem 138 and 140 is connected to the voice channel only when a data burst is to be sent by the respective modem. Furthermore, when data is sent, the audio interface unit 132 disconnects the microphone 134 and/or the speaker 136 from the voice channel and the DPU 106 disconnects the voice channel from the PSTN 110, thus muting the voice signals to prevent voice-signal interference with the data channel and to prevent the conversing parties from hearing the data modulation.

FIG. 3 shows the format of a data burst 300. Each data burst 300 contains, preferably at its beginning, an "acquisition header" 302 to enable the receiving modems 138 and 140 to clock-synchronize with the bits of the data burst. Preferably, the acquisition header 302 contains the bit pattern 0101010101010101, which, we have determined, provides enough data transmissions for the receiving modems 138 and 140 to clock-synchronize, but does not reduce the throughput capacity ("bit efficiency") of the data channel by using additional bits.

A "synchronization word" 304 referably follows the acquisition header 302 and enables the receiving modems 138 and 140 to distinguish data signals from voice signals. Noise, fading and other imperfections in the voice channel can cause the receiving modems 138 and 140 to incorrectly receive one or more bits of the data burst 300. To compensate for these errors, the receiving modems 138 and 140 can treat ("recognize") a set of received bits as a synchronization word even if fewer than all of the bits match the expected synchronization word. An "error threshold" herein refers to the number of bits that can be received in error while still recognizing a set of received bits as a synchronization word.

Increasing the length of the synchronization word and/or decreasing the error threshold reduces the likelihood of recognizing a synchronization word when none is actually received (a "false start"), but it raises the likelihood that a valid synchronization word will not be recognized (a "missed start"). A missed start causes the system to retransmit a data burst and, consequently, reduces the bit efficiency of the data channel. On the other hand, decreasing the length of the synchronization word and/or increasing the error threshold raises the likelihood of a false start, which causes the system to inappropriately, albeit temporarily, mute the voice signals. We have determined that, in a typical cellular telephone voice channel, a 16-bit code synchronization word provides a reasonable tradeoff between erroneous recognition and failure to recognize a synchronization word. We prefer to use a variable error threshold, e.g. if the mobile unit controller 126 detects a high voice-to-data ratio, the controller can employ a larger error threshold to minimize disruption of the voice channel due to false starts without heavily impacting the data rate and, conversely, if the voice-to-data ratio it low, a smaller error threshold reduces the likelihood of retransmissions and therefore increases the bit efficiency of the data channel without heavily impacting the voice signals.

Returning to FIG. 3, a header 306 follows the synchronization word 304 in the data burst 300. The header 306 contains a bit count 308 of the number of data bits contained in the data burst 300 and a checksum 310 of the bit count 308. If the received checksum 310 fails to match the checksum calculated based on the received bit count 308, the voice signals are unmuted and the remainder of the data burst 300 is ignored. Thus, the checksum 310 provides an additional safeguard against erroneously recognizing data burst or incorrect length. Optionally, the mobile unit controller 130 can adjust the error threshold in response to the rate of false starts, i.e. the controller can increase the error threshold if the controller detects a high rate of false starts.

An HDLC (high-level data link control) subframe 312 follows the header 306 in the data burst 300. The HDLC subframe transports data according to a modified X.25 HDLC standard, i.e. without start/stop flags and without data transparency. Optionally, the data can be encrypted before being inserted into the HDLC subframe 312. We prefer HDLC to other protocols because it is an industry-standard protocol that guarantees accurate data delivery and enables half-duplex operation with a minimal turn-around delay at data rates used by the system.

Optionally, a (15,11) Hamming code is used to add four parity bits to each group of 11 bits in the HDLC subframe 312 to produce a series of 15-bit code words in a process known as "encoding" or "forward error correction" (FEC). FEC enables the receiving modems 138 and 140 to correct a single-bit error and to detect a double-bit error in any 15-bit code word. While other FEC schemes, such as a (7,4) code, are acceptable, we prefer to use the (15,11) code because it provides a good tradeoff between bit efficiency and an ability to correct error bits at a rate expected on a cellular telephone channel. This error correction mechanism can also provide an estimate of the data channel error rate. Preferably, the modems 138 and 140 use the following parity check matrix: ##EQU1## yielding a code-generation matrix: ##EQU2## where I11 is the identity matrix of dimension 11.

The sending modems 138 and 140 can interleave the bits of the HDLC subframe 312 to overcome errors that tend to occur in bursts carried over a fading, cellular telephone channel. The header 306 can also be forward error corrected and bit-interleaved.

Returning to FIG. 1, when a user subscribes for service on the radio telephone system 100, a service provider stores, in a non-volatile, non-user-modifiable memory (NVM) 142 of the mobile unit 104 associated with the subscriber, mobile identification information that corresponds to the subscriber. The subscriber prepays for the service and the service provider stores in the database 118 the amount of money prepaid, together with the same identification information that is stored in the memory 142 of the mobile unit 104. The database 118 is stored in a conventional manner, such as on disk, tape or in random-access memory (RAM).

When a user of the mobile unit 104 attempts to make a call, the mobile unit controller 130 causes the base station 102 to establish a voice channel connection between the mobile unit and the transmit portion of the DPU 106 over the link 108. The voice channel is blocked (muted) at both ends during this phase. Then the mobile unit controller 130 sends the desired telephone number together with the identification information stored in the memory 142 to the DPU 106 using the two modems 138 and 140, as described above. The DPU 106 accesses the database 118 to ascertain the balance of money in the account corresponding to the subscriber associated with the identification information. If the balance exceeds the initial cost, e.g. air time and toll charges for, e.g. one minute of, the proposed call, the DPU 106 permits the call by forwarding the desired telephone number to the PSTN 110 and causing the DPU PSTN interface 112 to extend the voice channel over the PSTN and the voice channel at the mobile is opened. On the other hand, if the balance does not exceed the initial cost of the proposed call, the DPU 106 sends an announcement over the voice channel to the caller and it sends a command, via the modems 138 and 140, to the mobile unit controller 130. The announcement notifies the caller that the call cannot be completed and, if the call originated at the mobile unit 104, the reason. The command causes the mobile unit 104 to terminate the call.

When another party attempts to make a call to the mobile unit 104, the DPU 106 causes the base station 102 to establish a voice channel connection between the mobile unit and the DPU over the link 108. The DPU 106 and the mobile unit 104 then exchange commands and data using the modems 138 and 140, as described above. The DPU 106 causes the mobile unit 104 to send to the DPU the identification information stored in the memory 142 of the mobile unit. The DPU then accesses the database 118 and permits or denies the call, as described above. Herein, a "call attempted over the mobile telephone unit" refers to a call to or from the mobile unit.

Every minute, for the duration of a call, the DPU 106 reduces the balance in the database 118 by the cost of the preceding minute and optionally sends, via the modems 138 and 140, the remaining balance to the mobile unit 104 for display on a display screen 144. If, after any such reduction, the balance does not exceed the cost of the next minute of the call, the DPU 106 can send an announcement over the voice channel to the parties and it sends a command, via the modems 138 and 140, that causes the mobile unit 104 to terminate the call.

Numerous changes can be made in the system specifically described herein without departing from the scope of the invention. For example, the identification information stored in the memory 142 of the mobile unit 104 can be sent to the DPU 106 without muting the voice channel since the voice channel does not extend from the mobile unit 104 to the dialed unit 116 when the DPU ascertains the balance in the subscriber's account and there is little chance of voice-signal interference with the data channel. Protocols other than HDLC and error correction schemes other than FEC can be used. On some channels, error correction might not be necessary.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US5376931 *21 Jan 199227 Dec 1994Motorola, Inc.Debit message authorization system for radio receivers
US5485486 *23 Mar 199416 Jan 1996Qualcomm IncorporatedMethod and apparatus for controlling transmission power in a CDMA cellular mobile telephone system
US5577100 *30 Jan 199519 Nov 1996Telemac Cellular CorporationMobile phone with internal accounting
US5592535 *2 Apr 19967 Jan 1997Alcatel Sel AktiengesellschaftMobile-radio network with debit accounts
US5682602 *1 Mar 199628 Oct 1997Sierra Wireless, Inc.Method and apparatus for decreasing modem retraining due to blank and burst signalling in analog cellular systems
US5722067 *23 Dec 199424 Feb 1998Freedom Wireless, Inc.Security cellular telecommunications system
US5748720 *7 Aug 19965 May 1998Nokia Telecommunications OyRemovable subscriber identification module for a mobile radio terminal
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US6389397 *23 Dec 199814 May 2002Lucent Technologies, Inc.User identification system using improved voice print identification processing
US6625438 *26 Feb 200123 Sep 2003Verisign, Inc.Prepay telecommunications system
US670456311 Aug 19999 Mar 2004Boston Communications Group, Inc.Systems and methods for prerating costs for a communication event
US6741687 *4 Mar 200225 May 2004Sprint Spectrum L.P.System and method for providing prepaid communications
US6836651 *30 Nov 200028 Dec 2004Telespree CommunicationsPortable cellular phone system having remote voice recognition
US6885877 *22 Jul 199926 Apr 2005Fujitsu LimitedPortable communication device and system using the portable communication device and attachment for a portable communication device
US690711625 Jul 200114 Jun 2005Telecommunication Systems Inc.Time balance based prepaid subscriber database and reporting
US6931538 *25 Sep 200016 Aug 2005Takashi SawaguchiPortable personal authentication apparatus and electronic system to which access is permitted by the same
US695918330 Jan 200125 Oct 2005Leap Wireless International, Inc.Operations method for providing wireless communication services and network and system for delivering same
US702417422 Jul 20024 Apr 2006Citibank, N.A.Method and system for data management in electronic payments transactions
US71492933 Jun 200212 Dec 2006Sprint Spectrum L.P.System and method for controlling data sessions in a wireless network
US7162220 *7 Jul 20039 Jan 2007Verisign, Inc.Prepay telecommunications system
US7197768 *9 Jul 200127 Mar 2007Advanced Micro Devices, Inc.Software modem for communicating data using encrypted data and unencrypted control codes
US7373136 *23 Jul 200113 May 2008Telemac CorporationMethod and system for data rating for wireless devices
US737316016 Jan 200213 May 2008Telefonaktiebolaget L M Ericsson (Publ)Method and device for indicating amounts of data in mobile networks
US7529563 *10 Jul 20005 May 2009Pitroda Satyan GSystem for distribution and use of virtual stored value cards
US75651426 Apr 200521 Jul 2009Telespree CommunicationsMethod and apparatus for secure immediate wireless access in a telecommunications network
US7664898 *1 Feb 200616 Feb 2010BroadcomMethod and system for efficient framing on addressed buses
US771135910 Sep 20074 May 2010Telespree CommunicationsPortable cellular phone system having automatic initialization
US772948422 Apr 20041 Jun 2010Sprint Spectrum L.P.System and method for providing prepaid communications
US77649613 Sep 200927 Jul 2010Telecommunication Systems, Inc.Mobile based area event handling when currently visited network does not cover area
US780935924 Feb 20095 Oct 2010Telecommunication Systems, Inc.Wireless chat automatic status tracking
US780938211 Apr 20015 Oct 2010Telecommunication Systems, Inc.Short message distribution center
US784020818 Nov 200823 Nov 2010Telecommunication Systems, Inc.Intelligent queue for information teleservice messages with superceding updates
US784428514 Jun 200430 Nov 2010Telecommunication Systems, Inc.Intelligent queue for information teleservice messages with superseding updates
US785327221 Dec 200114 Dec 2010Telecommunication Systems, Inc.Wireless network tour guide
US785351118 Aug 200814 Dec 2010Telecommunication Systems, Inc.Prepaid short messaging
US78600683 Jan 200528 Dec 2010Telecommunication Systems, Inc.Intelligent delivery agent for short message distribution center
US78654317 Nov 20014 Jan 2011Panasonic CorporationPrivate electronic value bank system
US78698003 May 201011 Jan 2011Telespree CommunicationsPortable cellular phone system having automatic initialization
US78901025 Sep 200815 Feb 2011TeleCommunicationUser plane location based service using message tunneling to support roaming
US78901273 Mar 200815 Feb 2011Telecommunication Systems, Inc.Inter-carrier messaging service providing phone number only experience
US789479723 Feb 200922 Feb 2011Telecommunication Systems, Inc.Wireless chat automatic status signaling
US789482521 Jul 200622 Feb 2011Telecommunication Systems, Inc.Mobile activity status tracker
US790379113 Jun 20058 Mar 2011Telecommunication Systems, Inc.Enhanced E911 location information using voice over internet protocol (VoIP)
US79040724 Sep 20078 Mar 2011Telespree CommunicationsMethod and apparatus for secure immediate wireless access in a telecommunications network
US790755115 Aug 200615 Mar 2011Telecommunication Systems, Inc.Voice over internet protocol (VoIP) location based 911 conferencing
US791244626 Jun 200722 Mar 2011Telecommunication Systems, Inc.Solutions for voice over internet protocol (VoIP) 911 location services
US79295301 Dec 200819 Apr 2011Telecommunication Systems, Inc.Ancillary data support in session initiation protocol (SIP) messaging
US793361531 Mar 200926 Apr 2011Telecommunication Systems, Inc.Mobile originated interactive menus via short messaging services method
US794502630 May 200617 May 2011Telecommunications Systems, Inc.Voice over internet protocol (VoIP) E911 metro street address guide (MSAG) validation
US79497731 Feb 200724 May 2011Telecommunication Systems, Inc.Wireless internet gateway
US79660135 Nov 200721 Jun 2011Telecommunication Systems, Inc.Roaming gateway enabling location based services (LBS) roaming for user plane in CDMA networks without requiring use of a mobile positioning center (MPC)
US79914117 Oct 20042 Aug 2011Telecommunication Systems, Inc.Method to qualify multimedia message content to enable use of a single internet address domain to send messages to both short message service centers and multimedia message service centers
US801936827 Oct 201013 Sep 2011Telecommunication Systems, Inc.Intelligent queue for information teleservice messages with superceding updates
US803211217 Jan 20084 Oct 2011Telecommunication Systems, Inc.Location derived presence information
US804658126 Mar 200725 Oct 2011Telespree CommunicationsMethod and apparatus for secure immediate wireless access in a telecommunications network
US80597891 Dec 200615 Nov 2011Telecommunication Systems, Inc.Automatic location identification (ALI) emergency services pseudo key (ESPK)
US806042921 Nov 200815 Nov 2011Telecommunication Systems, Inc.Prepaid short messaging
US806858721 Aug 200929 Nov 2011Telecommunication Systems, Inc.Nationwide table routing of voice over internet protocol (VOIP) emergency calls
US807347716 Aug 20106 Dec 2011Telecommunication Systems, Inc.Short message distribution center
US809910510 Oct 200617 Jan 2012Telecommunication Systems, Inc.Device based trigger for location push event
US812645811 Feb 201128 Feb 2012Telecommunication Systems, Inc.User plane location based service using message tunneling to support roaming
US815036316 Feb 20063 Apr 2012Telecommunication Systems, Inc.Enhanced E911 network access for call centers
US81759538 Nov 20118 May 2012Telecommunication Systems, Inc.Prepaid short messaging
US818508717 Sep 200822 May 2012Telecommunication Systems, Inc.Emergency 911 data messaging
US819015117 May 201129 May 2012Telecommunication Systems, Inc.Roaming gateway enabling location based services (LBS) roaming for user plane in CDMA networks without requiring use of a mobile positioning center (MPC)
US81952057 Oct 20045 Jun 2012Telecommunication Systems, Inc.Gateway application to support use of a single internet address domain for routing messages to multiple multimedia message service centers
US820860527 Nov 200726 Jun 2012Telecommunication Systems, Inc.Extended efficient usage of emergency services keys
US82442189 Sep 201114 Aug 2012Telecommunication Systems, Inc.Intelligent queue for information teleservice messages with superceding updates
US824422016 Feb 201114 Aug 2012Telecommunication Systems, Inc.Wireless chat automatic status tracking
US824958919 Jul 201021 Aug 2012Telecommunication Systems, Inc.Mobile based area event handling when currently visited network does not cover area
US82603297 Mar 20084 Sep 2012Telecommunication Systems, Inc.Mobile-originated to HTTP communications
US8265663 *17 Dec 200211 Sep 2012Nokia CorporationMessaging services for pre-pay users
US82656732 Dec 201111 Sep 2012Telecommunication Systems, Inc.Short message distribution center
US8320539 *26 Feb 200827 Nov 2012Idi Billing SolutionsAdvanced payment for telephone services
US83698252 Apr 20125 Feb 2013Telecommunication Systems, Inc.Enhanced E911 network access for a call center using session initiation protocol (SIP) messaging
US838588110 Mar 201126 Feb 2013Telecommunication Systems, Inc.Solutions for voice over internet protocol (VoIP) 911 location services
US83859647 Jun 201126 Feb 2013Xone, Inc.Methods and apparatuses for geospatial-based sharing of information by multiple devices
US8401550 *1 Jun 200719 Mar 2013At&T Intellectual Property Ii, L.P.Method and apparatus for providing a pass to access multimedia services in a limited geographical area
US84067282 Apr 201226 Mar 2013Telecommunication Systems, Inc.Enhanced E911 network access for call centers
US846328417 Jul 200611 Jun 2013Telecommunication Systems, Inc.Short messaging system (SMS) proxy communications to enable location based services in wireless devices
US846732013 Sep 200618 Jun 2013Telecommunication Systems, Inc.Voice over internet protocol (VoIP) multi-user conferencing
US848372927 Jul 20129 Jul 2013Telecommunication Systems, Inc.Inter-carrier messaging service providing phone number only experience
US85322773 Oct 201110 Sep 2013Telecommunication Systems, Inc.Location derived presence information
US853845811 Mar 200817 Sep 2013X One, Inc.Location sharing and tracking using mobile phones or other wireless devices
US857733913 Aug 20125 Nov 2013Telecommunication Systems, Inc.Wireless chat automatic status signaling
US862616023 Feb 20127 Jan 2014Telecommunication Systems, Inc.User plane location based service using message tunneling to support roaming
US863061631 Aug 201214 Jan 2014Intel CorporationOperations method for providing wireless communication services
US86605736 Oct 200525 Feb 2014Telecommunications Systems, Inc.Location service requests throttling
US866639722 Dec 20114 Mar 2014Telecommunication Systems, Inc.Area event handling when current network does not cover target area
US868232122 Feb 201225 Mar 2014Telecommunication Systems, Inc.Mobile internet protocol (IP) location
US868236211 Feb 201125 Mar 2014Telecommunication Systems, Inc.Inter-carrier messaging service providing phone number only experience
US8688075 *19 Sep 20071 Apr 2014West CorporationHandling insufficient account balance of subscribers
US868808715 Apr 20111 Apr 2014Telecommunication Systems, Inc.N-dimensional affinity confluencer
US868817413 Mar 20121 Apr 2014Telecommunication Systems, Inc.Integrated, detachable ear bud device for a wireless phone
US871244111 Apr 201329 Apr 2014Xone, Inc.Methods and systems for temporarily sharing position data between mobile-device users
US87124534 Dec 200929 Apr 2014Telecommunication Systems, Inc.Login security with short messaging
US87384967 May 201227 May 2014Telecommunication Systems, Inc.Prepaid short messaging
US874449128 Oct 20103 Jun 2014Telecommunication Systems, Inc.Wireless network tour guide
US875018322 Aug 201210 Jun 2014Patent Monetization Associates, L.P.Mobile-originated to HTTP communications
US875089818 Jan 201310 Jun 2014X One, Inc.Methods and systems for annotating target locations
US879857225 Feb 20135 Aug 2014Telecommunication Systems, Inc.Solutions for voice over internet protocol (VoIP) 911 location services
US87985937 May 20135 Aug 2014X One, Inc.Location sharing and tracking using mobile phones or other wireless devices
US879864530 Jan 20135 Aug 2014X One, Inc.Methods and systems for sharing position data and tracing paths between mobile-device users
US879864715 Oct 20135 Aug 2014X One, Inc.Tracking proximity of services provider to services consumer
US88315561 Oct 20129 Sep 2014Telecommunication Systems, Inc.Unique global identifier header for minimizing prank emergency 911 calls
US883163521 Jul 20119 Sep 2014X One, Inc.Methods and apparatuses for transmission of an alert to multiple devices
US886748511 Sep 200921 Oct 2014Telecommunication Systems, Inc.Multiple location retrieval function (LRF) network having location continuity
US88737181 Mar 201128 Oct 2014Telecommunication Systems, Inc.Enhanced E911 location information using voice over internet protocol (VoIP)
US887406827 Mar 201228 Oct 2014Telecommunication Systems, Inc.Emergency 911 data messaging
US888579625 Jun 201211 Nov 2014Telecommunications Systems, Inc.Extended efficient usage of emergency services keys
US889212113 Jan 201218 Nov 2014Telecommunication Systems, Inc.Device based trigger for location push event
US89139833 May 201116 Dec 2014Telecommunication Systems, Inc.Voice over internet protocol (VoIP) E911 metro street address guide (MSAG) validation
US8913988 *4 Mar 201416 Dec 2014West CorporationHandling insufficient account balance of subscribers
US892985424 Oct 20126 Jan 2015Telecommunication Systems, Inc.Emergency text messaging
US894274328 Dec 201127 Jan 2015Telecommunication Systems, Inc.iALERT enhanced alert manager
US895402828 Oct 200810 Feb 2015Telecommunication Systems, Inc.Geo-redundant and high reliability commercial mobile alert system (CMAS)
US89653608 Nov 201324 Feb 2015Telecommunication Systems, Inc.User plane location based service using message tunneling to support roaming
US898304720 Mar 201417 Mar 2015Telecommunication Systems, Inc.Index of suspicion determination for communications request
US89830489 Sep 201317 Mar 2015Telecommunication Systems, Inc.Location derived presence information
US898459117 Dec 201217 Mar 2015Telecommunications Systems, Inc.Authentication via motion of wireless device movement
US900295125 Sep 20077 Apr 2015Telecommunication Systems, Inc.Web gateway multi-carrier support
US90315817 Nov 201412 May 2015X One, Inc.Apparatus and method for obtaining content on a cellular wireless device based on proximity to other wireless devices
US907781712 Nov 20147 Jul 2015Telecommunication Systems, Inc.Voice over internet protocol (VoIP) E911 metro street address guide (MSAG) validation
US90886147 Mar 201421 Jul 2015Telecommunications Systems, Inc.User plane location services over session initiation protocol (SIP)
US911878013 Dec 201325 Aug 2015Intel CorporationOperations method for providing wireless communication services
US912503910 Feb 20141 Sep 2015Telecommunication Systems, Inc.Enhanced E911 network access for a call center using session initiation protocol (SIP) messaging
US91309636 Apr 20118 Sep 2015Telecommunication Systems, Inc.Ancillary data support in session initiation protocol (SIP) messaging
US913135723 Sep 20148 Sep 2015Telecommunication Systems, Inc.Emergency 911 data messaging
US915490624 Feb 20066 Oct 2015Telecommunication Systems, Inc.Area watcher for wireless network
US916057217 Oct 200713 Oct 2015Telecommunication Systems, Inc.Automated location determination to support VoIP E911 using self-surveying techniques for ad hoc wireless network
US916118916 Oct 200613 Oct 2015Telecommunication Systems, Inc.Automatic call forwarding to in-vehicle telematics system
US916755812 Jun 201420 Oct 2015X One, Inc.Methods and systems for sharing position data between subscribers involving multiple wireless providers
US917282116 Oct 201427 Oct 2015Telecommunication Systems, Inc.Wireless internet gateway limiting message distribution
US91730595 Mar 201427 Oct 2015Telecommunication Systems, Inc.Mobile internet protocol (IP) location
US917899631 Jul 20143 Nov 2015Telecommunication Systems, Inc.Unique global identifier header for minimizing prank 911 calls
US91855227 Nov 201410 Nov 2015X One, Inc.Apparatus and method to transmit content to a cellular wireless device based on proximity to other wireless devices
US919152012 Dec 201117 Nov 2015Telecommunication Systems, Inc.Location services gateway server
US9191524 *9 Dec 201417 Nov 2015West CorporationHandling insufficient account balance of subscribers
US919799223 Jun 201524 Nov 2015Telecommunication Systems, Inc.User plane location services over session initiation protocol (SIP)
US920427710 Dec 20141 Dec 2015Telecommunication Systems, Inc.Emergency text messaging
US92083465 Sep 20138 Dec 2015Telecommunication Systems, Inc.Persona-notitia intellection codifier
US921054810 Dec 20148 Dec 2015Telecommunication Systems, Inc.iALERT enhanced alert manager
US921822918 Nov 200822 Dec 2015Telecommunication Systems, Inc.Event notification system and method
US922095815 Oct 201229 Dec 2015Telecommunications Systems, Inc.Consequential location derived information
US924104011 Feb 201119 Jan 2016Telecommunication Systems, Inc.Mobile activity status tracker
US925361624 Mar 20152 Feb 2016X One, Inc.Apparatus and method for obtaining content on a cellular wireless device based on proximity
US927113814 Jan 201523 Feb 2016Telecommunication Systems, Inc.User plane location based service using message tunneling to support roaming
US928245113 Dec 20058 Mar 2016Telecommunication Systems, Inc.Automatic location identification (ALI) service requests steering, connection sharing and protocol translation
US928861524 Feb 201415 Mar 2016Telecommunication Systems, Inc.Location service requests throttling
US929491110 May 201122 Mar 2016Telecommunication Systems, Inc.Cell-ID translation in a location based system (LBS)
US930119117 Oct 201329 Mar 2016Telecommunication Systems, Inc.Quality of service to over the top applications used with VPN
US930737219 Mar 20135 Apr 2016Telecommunication Systems, Inc.No responders online
US931363730 Nov 201212 Apr 2016Telecommunication Systems, Inc.Wireless emergency caller profile data delivery over a legacy interface
US931363815 Aug 201312 Apr 2016Telecommunication Systems, Inc.Device independent caller data access for emergency calls
US93261439 Feb 201526 Apr 2016Telecommunication Systems, Inc.Authentication via motion of wireless device movement
US933815310 Apr 201310 May 2016Telecommunication Systems, Inc.Secure distribution of non-privileged authentication credentials
US936929425 Nov 200814 Jun 2016Telecommunication Systems, Inc.Reverse 911 using multicast session internet protocol (SIP) conferencing of voice over internet protocol (VoIP) users
US93843398 Jan 20135 Jul 2016Telecommunication Systems, Inc.Authenticating cloud computing enabling secure services
US93984194 Feb 201519 Jul 2016Telecommunication Systems, Inc.Location derived presence information
US940198611 Sep 201526 Jul 2016Telecommunication Systems, Inc.Unique global identifier header for minimizing prank emergency 911 calls
US940803429 Aug 20142 Aug 2016Telecommunication Systems, Inc.Extended area event for network based proximity discovery
US940804620 Jun 20072 Aug 2016Telecommunication Systems, Inc.911 data messaging
US94080478 Oct 20142 Aug 2016Telecommunication Systems, Inc.Read acknowledgement interoperability for text messaging and IP messaging
US942044425 Mar 201316 Aug 2016Telecommunication Systems, Inc.Enhanced E911 network access for call centers
US943252217 Aug 201530 Aug 2016Intel CorporationOperations method for providing wireless communication services
US9432524 *17 Nov 201530 Aug 2016West CorporationHandling insufficient account balance of subscribers
US945139431 Dec 201220 Sep 2016Elwha LlcCost-effective mobile connectivity protocols
US945630111 Dec 201327 Sep 2016Telecommunication Systems, Inc.Efficient prisoner tracking
US946782625 Aug 201511 Oct 2016Telecommunications Systems, Inc.Emergency 911 data messaging
US94678325 Sep 201411 Oct 2016X One, Inc.Methods and systems for temporarily sharing position data between mobile-device users
US946783622 Sep 201411 Oct 2016Telecommunication Systems, Inc.Enhanced E911 location information using voice over internet protocol (VoIP)
US946784418 Aug 201511 Oct 2016Telecommunication Systems, Inc.Mobile activity status tracker
US947934411 Sep 201225 Oct 2016Telecommunication Systems, Inc.Anonymous voice conversation
US94798971 Oct 201425 Oct 2016Telecommunication Systems, Inc.SUPL-WiFi access point controller location based services for WiFi enabled mobile devices
US950345025 Apr 201422 Nov 2016Telecommunications Systems, Inc.Login security with short messaging
US951014320 Oct 201429 Nov 2016Telecommunications Systems, Inc.Device based trigger for location push event
US951610410 Sep 20146 Dec 2016Telecommunication Systems, Inc.Intelligent load balancer enhanced routing
US95198888 May 200713 Dec 2016Telecommunication Systems, Inc.End use transparent email attachment handling to overcome size and attachment policy barriers
US954426019 Mar 201310 Jan 2017Telecommunication Systems, Inc.Rapid assignment dynamic ownership queue
US95846616 Oct 201428 Feb 2017Telecommunication Systems, Inc.Extended efficient usage of emergency services keys
US958496023 Dec 201328 Feb 2017X One, Inc.Rendez vous management using mobile phones or other mobile devices
US959658431 Oct 201314 Mar 2017Elwha LlcProtocols for facilitating broader access in wireless communications by conditionally authorizing a charge to an account of a third party
US959971731 Jul 201421 Mar 2017Telecommunication Systems, Inc.Wireless telecommunications location based services scheme selection
US960296827 Aug 201421 Mar 2017Telecommunication Systems, Inc.Area watcher for wireless network
US9614980 *30 Aug 20164 Apr 2017West CorporationHandling insufficient account balance of subscribers
US961520422 Jul 20154 Apr 2017X One, Inc.Techniques for communication within closed groups of mobile devices
US96356053 Jun 201325 Apr 2017Elwha LlcProtocols for facilitating broader access in wireless communications
US965492120 Sep 201616 May 2017X One, Inc.Techniques for sharing position data between first and second devices
US9693214 *15 Mar 201327 Jun 2017Elwha LlcProtocols for facilitating broader access in wireless communications
US970606030 Jul 201311 Jul 2017Elwha LlcProtocols for facilitating broader access in wireless communications
US970638228 Jun 201311 Jul 2017Elwha LlcProtocols for allocating communication services cost in wireless communications
US97130133 Jun 201318 Jul 2017Elwha LlcProtocols for providing wireless communications connectivity maps
US973661816 Jul 201515 Aug 2017X One, Inc.Techniques for sharing relative position between mobile devices
US974979012 Jan 201729 Aug 2017X One, Inc.Rendez vous management using mobile phones or other mobile devices
US20010000505 *30 Nov 200026 Apr 2001Edna SegalPortable cellular phone system having remote voice recognition
US20010029524 *11 Apr 200111 Oct 2001Richard SmithUniversal mail wireless e-mail reader
US20020022471 *23 Jul 200121 Feb 2002Telemac CorporationMethod and system for data rating for wireless devices
US20020119793 *27 Feb 200129 Aug 2002Daniel HronekMobile originated interactive menus via short messaging services
US20020133568 *20 Feb 200119 Sep 2002Smith Richard A.Individualized network information server
US20020160808 *26 Dec 200031 Oct 2002Keiji UeharaMobile radio apparatus
US20030009678 *9 Jul 20019 Jan 2003Cole Terry L.Software modem for communicating data using encrypted data and unencrypted control codes
US20040063424 *27 Sep 20021 Apr 2004Silberstein Eli J.System and method for preventing real-time and near real-time fraud in voice and data communications
US20040098293 *7 Jul 200320 May 2004Hanson Daniel A.Prepay telecommunications system
US20040103063 *7 Nov 200127 May 2004Hisashi TakayamaPrivate electronic value bank system
US20040106422 *16 Jan 20023 Jun 2004Andreas EricssonMethod and device for indicating amounts of data in mobile networks
US20040117312 *17 Dec 200217 Jun 2004Elena LialiamouMessaging services for pre-pay users
US20040148237 *29 Jan 200329 Jul 2004Msafe Ltd.Real time management of a communication network account
US20050181793 *6 Apr 200518 Aug 2005Eran NetanelMethod and apparatus for secure immediate wireless access in a telecommunications network
US20070180173 *1 Feb 20062 Aug 2007Changxi JinMethod and system for efficient framing on addressed buses
US20070300294 *4 Sep 200727 Dec 2007Eran NetanelMethod and Apparatus for Secure Immediate Wireless Access in a Telecommunications Network
US20080020755 *9 May 200724 Jan 2008Mino Holdings, Inc.Method and system for international roaming using virtual sim card
US20080026740 *26 Mar 200731 Jan 2008Eran NetanelMethod and apparatus for secure immediate wireless access in a telecommunications network
US20080057935 *10 Sep 20076 Mar 2008Eran NetanelPortable cellular phone system having automatic initialization
US20090025070 *23 Jul 200822 Jan 2009Eran NetanelSystem and method to enable subscriber self-activation of wireless data terminals
US20090075627 *19 Sep 200719 Mar 2009West CorporationHandling insufficient account balance of subscribers
US20090190730 *3 Apr 200930 Jul 2009Jing LiuMethod and System for Using Advertisement to Sponsor International Mobile Phone Calls for Cellular Telephone Networks
US20090214012 *26 Feb 200827 Aug 2009Ingalsbe Jason MAdvanced payment for telephone services
US20090245179 *13 Apr 20091 Oct 2009Jing LiuMethod and System for Processing International Calls Using a Voice Over IP Process
US20090280846 *24 Feb 200912 Nov 2009Dara UngWireless chat automatic status tracking
US20100003976 *3 Sep 20097 Jan 2010Yinjun ZhuMobile based area event handling when currently visited network does not cover area
US20100009659 *21 Jul 200914 Jan 2010Eran NetanelSystem and Method to Enable Subscriber Self-Activation of Wireless Data Terminals
US20100088751 *17 Sep 20098 Apr 2010Fujitsu LimitedCommunication system, terminal control unit and communication method
US20100210264 *3 May 201019 Aug 2010Eran NetanelPortable cellular phone system having automatic initialization
US20140273931 *15 Mar 201318 Sep 2014Elwha LlcProtocols for facilitating broader access in wireless communications
USRE41803 *11 Jan 20065 Oct 2010Cricket Communications, Inc.Operations method of providing wireless communication service and network and system for delivering same
EP1341105A1 *7 Nov 20013 Sep 2003Matsushita Electric Industrial Co., Ltd.Private electronic value bank system
WO2004030320A2 *26 Sep 20038 Apr 2004Idt CorporationSystem and method for preventing real-time and near real-time fraud in voice and data communications
WO2004030320A3 *26 Sep 200316 Jun 2005Idt CorpSystem and method for preventing real-time and near real-time fraud in voice and data communications
Classifications
U.S. Classification455/406, 455/407, 455/410, 455/405
International ClassificationH04M17/00, H04W88/02
Cooperative ClassificationH04M15/765, H04M2215/8166, H04M15/77, H04M17/00, H04M2215/724, H04M15/854, H04M17/10, H04M2215/7254, H04M2215/32, H04W88/02
European ClassificationH04M15/765, H04M15/77, H04M15/85D, H04M17/10, H04M17/00
Legal Events
DateCodeEventDescription
15 Aug 1996ASAssignment
Owner name: JRC CANADA, TEXAS
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:BARABASH, DARRELL;MORRIS, RUSSELL;REEL/FRAME:008176/0536
Effective date: 19960814
23 May 2000ASAssignment
Owner name: JAPAN RADIO CO., LTD., JAPAN
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:JRC CANADA, INC.;REEL/FRAME:010844/0757
Effective date: 20000313
9 Feb 2004FPAYFee payment
Year of fee payment: 4
8 Feb 2008FPAYFee payment
Year of fee payment: 8
19 Mar 2012REMIMaintenance fee reminder mailed
8 Aug 2012LAPSLapse for failure to pay maintenance fees
25 Sep 2012FPExpired due to failure to pay maintenance fee
Effective date: 20120808